View Full Version : 99 4.0L Upper intake removal
08-23-2007, 12:08 PM
I haven't posted for quite a while so I just had to re-register.
I am trying to remove the upper intake manifold and can't get the EGR out of the hole in the plastic manifold. The studs are preventing me from moving the manifold away from the EGR tube so it will come out.
Trying to stop an antifreeze leak into #1 cyl. Runs great.
Have you done a cylinder leakdown test on #1?
'Cause while a blown lower intake is a possibility, a much more serious blown head or head gasket is a very obvious candidate.
Diagnose BEFORE you rip the engine apart or you may not be able to.
Most EGRs can be removed from both ends if necessary. Use lots of penetrating lubricant.
08-23-2007, 01:12 PM
Thanks for the reply.
I have never done a leakdown test. Can you point me in the right direction for information on it?
I have been able to remove the upper intake successfully. I can see a lot of moisture in the #1 port but that is all.
To go any further I will have to remove the fuel rail but first I think I will have to remove the studs. Any advise on that?
DON'T remove the fuel rail unless you absolutely have to. 4.0L rails can be a challenge to get back on. The earlier ones at least have E-7 studs if you really have to go there. I'd suggest disconnecting both fuel lines from the rail and removing the rail/lower intake still assembled.
Unless you're checking piston rings, a "good enough" leakdown test is to pressurize the cylinder to 100 PSI at TDC/compression and see if any bubbles come out the (open) radiator neck. Obviously, this has to be done while there is still coolant in the radiator. You can also very easily listen at the throttle body and exhaust pipe for hissing -- this finds valve problems, though there is no evidence of that elsewhere. If you don't have the equipment for this, almost any mechanic can do it for you cheaply.
08-23-2007, 02:06 PM
Thanks again for the replies.
I will try to obtain a leak down tester from our local Autozone.
I haven't found any antifreeze in the oil. The only symptoms are it uses antifreeze and the #1 plug has fouled a few times. There is also a white build up between the exhaust manifold and #1 exhaust port. Slight leak there. Other than that is runs great.
I am now in a hurry since my company has asked me to go to work away from home in 2 weeks. Haven't worked in 2 years but have been working on our 55 Chevy and ignored the Ranger (me bad).
08-24-2007, 01:33 PM
Well I found out we have 2 cracked heads. They are cracked between the valves on one cylinder each.
I had made sort of a leak down tester using a sparkplug adapter and on old regulator and short 1/4" air hose I had. After I removed the upper intake I could see air bubling up past the intake valve on #4 cyl. and hear it in the water passage.
I have located new heads for it locally for about $300 each using my valves and springs.
Ouch. Sorry for the bad news.
Did it overheat?
The spot you describe is an obvious weak spot in quite a number of heads. It's quite close to where older 2.9L heads crack as well.
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